Tethering Mps1 to kinetochores extends metaphase. (A) Immunolocalization of LAP-Mis12-Mps1(-WT) in U2OS during indicated phases of cell cycle. (B) Percentage of mitotic (Mpm2 positive) U2OS cells that were transfected and treated as indicated, as determined by flow cytometry. Immunoblot shows levels of LAP-Mps1 and LAP-Mis12-Mps1 in total cell lysate. (C and D) Time spent in prometaphase and metaphase of transiently transfected U2OS cells with indicated plasmids and treated as indicated. Each horizontal bar represents a single cell.